1. Field of the Invention
The present invention relates to a sensor for detecting volatile organic compounds and, more particularly, to a volatile organic compound sensor of an ionization method, which adopts a cheap light source and uses accelerated photoemission electrons.
2. Description of the Related Art
Volatile organic compounds (VOC) whose amount is suddenly increased in a living environment have a bad influence on the human body in many aspects, such as the induction of cancer and skin diseases such as atopic dermatitis.
In general, such VOCs are present in a gaseous state at normal temperature and in atmospheric pressure. In Clean Air Conservation Act of Korea, petrochemicals, organic solvents and other materials of hydrocarbon series officially announced by the Minister of Environment have been defined as the VOCs, but are not limited thereto. The VOCs may include all of organic compounds ionized in energy of a specific amount (e.g., 9 eV) or higher.
As the emission quantity of VOCs increases, a need to detect VOCs also increases. In general, a conventional VOC sensor for detecting VOCs may be divided into a photoionization (PID) method and a semiconductor type resistance change method. The photoionization method has a disadvantage in that a production cost is high because an expensive light source is used. Furthermore, the semiconductor type resistance change method has a problem in that sensitivity is very low compared to the photoionization method. Accordingly, there is a need for the development of a VOC sensor of a new method, which is cheap while maintaining a specific level or more of sensitivity.